Systematic pulmonary embolism follow-up increases diagnostic rates of chronic thromboembolic pulmonary hypertension and identifies less severe disease: results from the ASPIRE Registry.

BACKGROUND: Diagnostic rates and risk factors for the subsequent development of chronic thromboembolic pulmonary hypertension (CTEPH) following pulmonary embolism (PE) are not well defined. METHODS: Over a 10-year period (2010-2020), consecutive patients attending a PE follow-up clinic in Sheffield, UK (population 554 600) and all patients diagnosed with CTEPH at a pulmonary hypertension (PH) referral centre in Sheffield (referral population estimated 15-20 million) were included. RESULTS: Of 1956 patients attending the Sheffield PE clinic 3 months following a diagnosis of acute PE, 41 were diagnosed with CTEPH with a cumulative incidence of 2.10%, with 1.89% diagnosed within 2 years. Of 809 patients presenting with pulmonary hypertension (PH) and diagnosed with CTEPH, 32 were Sheffield residents and 777 were non-Sheffield residents. Patients diagnosed with CTEPH at the PE follow-up clinic had shorter symptom duration (p<0.01), better exercise capacity (p<0.05) and less severe pulmonary haemodynamics (p<0.01) compared with patients referred with suspected PH. Patients with no major transient risk factors present at the time of acute PE had a significantly higher risk of CTEPH compared with patients with major transient risk factors (OR 3.6, 95% CI 1.11-11.91; p=0.03). The presence of three computed tomography (CT) features of PH in combination with two or more out of four features of chronic thromboembolic pulmonary disease at the index PE was found in 19% of patients who developed CTEPH and in 0% of patients who did not. Diagnostic rates and pulmonary endarterectomy (PEA) rates were higher at 13.2 and 3.6 per million per year, respectively, for Sheffield residents compared with 3.9-5.2 and 1.7-2.3 per million per year, respectively, for non-Sheffield residents. CONCLUSIONS: In the real-world setting a dedicated PE follow-up pathway identifies patients with less severe CTEPH and increases population-based CTEPH diagnostic and PEA rates. At the time of acute PE diagnosis the absence of major transient risk factors, CT features of PH and chronic thromboembolism are risk factors for a subsequent diagnosis of CTEPH.

Caution in Using the Activated Partial Thromboplastin Time to Monitor Argatroban in COVID-19 and Vaccine-Induced Immune Thrombocytopenia and Thrombosis (VITT).

INTRODUCTION: Argatroban is licensed for patients with heparin-induced thrombocytopenia and is conventionally monitored by activated partial thromboplastin time (APTT) ratio. The target range is 1.5 to 3.0 times the patients' baseline APTT and not exceeding 100 s, however this baseline is not always known. APTT is known to plateau at higher levels of argatroban, and is influenced by coagulopathies, lupus anticoagulant and raised FVIII levels. It has been used as a treatment for COVID-19 and Vaccine-induced Immune Thrombocytopenia and Thrombosis (VITT). Some recent publications have favored the use of anti-IIa methods to determine the plasma drug concentration of argatroban. METHODS: Plasma of 60 samples from 3 COVID-19 patients and 54 samples from 5 VITT patients were tested by APTT ratio and anti-IIa method (dilute thrombin time dTT). Actin FS APTT ratios were derived from the baseline APTT of the patient and the mean normal APTT. RESULTS: Mean APTT ratio derived from baseline was 1.71 (COVID-19), 1.33 (VITT) compared to APTT ratio by mean normal 1.65 (COVID-19), 1.48 (VITT). dTT mean concentration was 0.64 µg/ml (COVID-19) 0.53 µg/ml (VITT) with poor correlations to COVID-19 baseline APTT ratio r2 = 0.1526 p <0.0001, mean normal r2 = 0.2188 p < 0.0001; VITT baseline APTT ratio r2 = 0.04 p < 0.001, VITT mean normal r2 = 0.0064 p < 0.001. CONCLUSIONS: We believe that dTT is a superior method to monitor the concentration of argatroban, we have demonstrated significant differences between APTT ratios and dTT levels, which could have clinical impact. This is especially so in COVID-19 and VITT.

Platelet cut-off for anticoagulant therapy in thrombocytopenic patients with blood cancer and venous thromboembolism: an expert consensus.

BACKGROUND: Management of venous thromboembolism (VTE) in patients with haematologic malignancies and thrombocytopenia is clinically challenging due to the related risks. No prospective studies or clinical trials have been carried out and, therefore, no solid evidence on this compelling issue is available. METHODS: Given this, an expert panel endorsed by the Gruppo Italiano Malattie Ematologiche dell'Adulto Working Party on Thrombosis and Haemostasis was set up to produce a formal consensus, according to the RAND method, in order to issue clinical recommendations about the platelet (PLT) cut-off for safe administration of low molecular weight heparin (LMWH) in thrombocytopenic (PLT <100×109/L) adult patients with haematologic malignancies affected by acute (<1 month) or non-acute VTE. RESULTS: In acute VTE, the panel suggests safe anticoagulation with LMWH at therapeutic doses for PLT between ≥50<100×109/L and at 50% dose reduction for PLT ≥30<50×109/L. In acute VTE for PLT <30×109/L, the following interventions are recommended: positioning of an inferior vena cava (IVC) filter with prophylactic LMWH administration and platelet transfusion. In non-acute VTE, anticoagulation with LMWH at therapeutic doses for PLT between ≥50<100×109/L or over and at 50% dose reduction for PLT ≥30<50×109/L is considered appropriate. The discontinuation of full or reduced therapeutic dose of LMWH is recommended for PLT <30×109/L, both in acute and non-acute VTE. DISCUSSION: We suggest using dose-adjusted LMWH according to PLT to optimise anticoagulant treatment in patients at high bleeding risk.

The current state of adverse event reporting in hemophilia.

INTRODUCTION: Replacement of the missing clotting factor is the mainstay of hemophilia treatment. Whilst historically many hemophilia patients were infected with blood-borne viruses transmitted via plasma-derived products, nowadays the formation of alloantibodies against the missing clotting factor is the main adverse event of treatment. Areas covered: This paper provides an overview of the current national and international adverse event reporting systems, what these surveillance schemes taught us about side effects of the products presently in use, and elaborates on how to adapt these systems to the challenges we face with the changing treatment landscape. Expert commentary: Treatment of inherited bleeding disorders was accompanied by severe complications in the past, resulting in major morbidity and mortality. Current products are much safer, but still require monitoring via efficient safety surveillance systems. Adverse events are reported in national and international systems. With many new products entering the market, as well as non-factor replacement therapies, new safety issues may arise. It is important to identify potential adverse events early by making surveillance systems suitable to pick up unknown or unexpected effects, and to recognize and communicate patterns of adverse events rapidly.

Prophylaxis in von Willebrand Disease: Coming of Age?

Although in most cases von Willebrand disease (VWD) is a mild disorder, a subgroup of patients experience frequent bleeding. In contrast to severe hemophilia in which prophylaxis is the accepted standard of care, this is less frequently used in VWD. Most type 1 VWD patients can be adequately managed with episodic desmopressin and tranexamic acid. In patients with more severe disease, especially those with type 3 VWD, joint bleeds, epistaxis, menorrhagia, and gastrointestinal bleeding are problematic and usually require treatment with von Willebrand factor/factor VIII (VWF/FVIII) concentrate. While in the past these patients were managed with on-demand VWF/FVIII concentrate, several recent reports have demonstrated the value of prophylactic treatment. Despite some uncertainties about the economic impact of treatment of severe VWD, prophylaxis with VWF concentrate should now be considered as the standard of care for the more severe end of the spectrum of affected individuals. The recent introduction of recombinant VWF concentrate is likely to improve the acceptability of prophylaxis in VWD.

Management of venous thromboembolism in patients with acute leukemia at high bleeding risk: a multi-center study.

In the last decades, evaluation of clinically relevant thrombotic complications in patients with acute leukemia (AL) has been poorly investigated. The authors performed a multi-center study to evaluate the management of symptomatic venous thromboembolism (VTE) in adult patients with AL. The intention was to find as clinically relevant the following: symptomatic Venous Thrombosis (VT) occurred in typical (lower limbs) and atypical (cerebral, upper limbs, abdominal, etc) sites with or without pulmonary embolism (PE). Over a population of 1461 patients with AL, 22 cases of symptomatic VTE were recorded in hospitalized patients with a mean age of 54.6 years. The absolute incidence of VTE was 1.5%. VTE occurred during chemotherapy in 17/22 (77.2%) cases, mainly (14/17, 82.3%) during the induction phase. Treatment of acute VTE was based on Low Molecular Weight Heparin (LMWH) at full dosage for the first month from diagnosis and reduced dosage (75%) for the following months.

Optimal duration of low molecular weight heparin for the treatment of cancer-related deep vein thrombosis: the Cancer-DACUS Study.

PURPOSE: We evaluated the role of residual vein thrombosis (RVT) to assess the optimal duration of anticoagulants in patients with cancer who have deep vein thrombosis (DVT) of the lower limbs. PATIENTS AND METHODS: Patients with active cancer and a first episode of DVT treated with low molecular weight heparin (LMWH) for 6 months were eligible. Patients were managed according to RVT findings: those with RVT were randomly assigned to continue LMWH for an additional 6 months (group A1) or to discontinue it (group A2), and patients without RVT stopped LMWH (group B). The primary end point was recurrent venous thromboembolism (VTE) during the 1 year after disconinuation of LMWH, and the secondary end point was major bleeding. Analyses are from the time of random assignment. RESULTS: Between October 2005 and April 2010, 347 patients were enrolled. RVT was detected in 242 patients (69.7%); recurrence occurred in 22 of the 119 patients in group A1compared with 27 of 123 patients in group A2. The adjusted hazard ratio (HR) for group A2 versus A1 was 1.37 (95% CI, 0.7 to 2.5; P = .311). Three of the 105 patients in group B developed recurrent VTE; adjusted HR for group A1 versus B was 6.0 (95% CI, 1.7 to 21.2; P = .005). Three major bleeding events occurred in group A1, and two events each occurred in groups A2 and B. The HR for major bleeding in group A1 versus group A2 was 3.78 (95% CI, 0.77 to 18.58; P = .102). Overall, 42 patients (12.1%) died during follow-up as a result of cancer progression. CONCLUSION: In patients with cancer with a first DVT, treated for 6 months with LMWH, absence of RVT identifies a population at low risk for recurrent thrombotic events. Continuation of LMWH in patients with RVT up to 1 year did not reduce recurrent VTE.

Prognostic significance of residual venous obstruction in patients with treated unprovoked deep vein thrombosis: a patient-level meta-analysis.

Residual venous obstruction (RVO) could improve the stratification of the risk of recurrence after unprovoked deep vein thrombosis (DVT), but results from clinical studies and study-level meta-analyses are conflicting. It was the objective of this analysis to determine if RVO is a valid predictor of recurrent venous thromboembolism (VTE) in patients with a first unprovoked DVT who had received at least three months of anticoagulant therapy. Individual patient data were obtained from the datasets of original studies, after a systematic search of electronic databases (Medline, Embase, Cochrane Library), supplemented by manual reviewing of the reference lists and contacting content experts. A multivariate, shared-frailty Cox model was used to calculate hazard ratios (HRs) for recurrent VTE, including, as covariates: RVO; age; sex; anticoagulation duration before RVO assessment; and anticoagulation continuation after RVO assessment. A total of 2,527 patients from 10 prospective studies were included. RVO was found in 1,380 patients (55.1%) after a median of six months from a first unprovoked DVT. Recurrent VTE occurred in 399 patients (15.8%) during a median follow-up of 23.3 months. After multivariate Cox analysis, RVO was independently associated with recurrent VTE (HR = 1.32, 95% confidence interval [CI]: 1.06-1.65). The association was stronger if RVO was detected early, i.e. at three months after DVT (HR = 2.17; 95% CI: 1.11-4.25), but non-significant if detected later, i.e. >6 months (HR = 1.19; 95% CI: 0.87-1.61). In conclusion, after a first unprovoked DVT, RVO is a weak overall predictor of recurrent VTE. The association is stronger if RVO is detected at an earlier time (3 months) after thrombosis.

Ultrasonography-guided central venous catheterisation in haematological patients with severe thrombocytopenia.

BACKGROUND: Cannulation of the internal jugular vein (CVC) is a blind surface landmark-guided technique that could be potentially dangerous in patients with very low platelet counts. In such patients, ultrasonography (US)-guided CVC may be a valid approach. There is a lack of published data on the efficacy and safety of urgent US-guided CVC performed in haematological patients with severe thrombocytopenia. MATERIALS AND METHODS: We retrospectively studied the safety of urgent CVC procedures in haematological patients including those with severe thrombocytopenia (platelet count <30×10(9)/L). From January 1999 to June 2009, 431 CVC insertional procedures in 431 consecutive patients were evaluated. Patients were included in the study if they had a haematological disorder and required urgent CVC insertion. Patients were placed in Trendelenburg's position, an 18-gauge needle and guide-wire were advanced under real-time US guidance into the last part of the internal jugular vein; central venous cannulation of the internal jugular vein was performed using the Seldinger technique in all the procedures. Major and minor procedure-related complications were recorded. RESULTS: All 431 patients studied had haematological disorders: 39 had severe thrombocytopenia, refractory to platelet transfusion (group 1), while 392 did not have severe thrombocytopenia (group 2). The general characteristics of the patients in the two groups differed only for platelet count. The average time taken to perform the procedure was 4 minutes. Success rates were 97.4% and 97.9% in group 1 and group 2, respectively. No major complications occurred in either group. DISCUSSION: US-guided CVC is a safe and effective approach in haematological patients with severe thrombocytopenia requiring urgent cannulation for life support, plasma-exchange, chemotherapy and transfusion.

Cancer patients requiring interruption of long-term warfarin because of surgery or chemotherapy induced thrombocytopenia: the use of fixed sub-therapeutic doses of low-molecular weight heparin.

No data are available regarding the management of cancer patients requiring interruption of long-term vitamin-K antagonist (VKA) therapy. For this purpose, we tested the efficacy and safety of fixed doses of low-molecular weight heparin (LMWH) in substitution of VKA because of invasive procedures or chemotherapy-induced thrombocytopenia. In cancer patients on VKA, therapy was discontinued 5 ± 1 days before surgery or chemotherapy. Heparin was given at prophylactic dosage in patients at low risk and at fixed subtherapeutic doses (3,800 or 4,000 UI anti-FXa, b.i.d.) in those at high-risk for thrombosis. LMWH was reinitiated 12 hr after surgery and VKA the day after. In patients receiving chemotherapy, LMWH was reinitiated 12/24 hr after obtaining a stable platelet count ≥ 30,000 mmc(3) and VKA after a stable platelet count ≥ 50,000 mmc(3) . Thromboembolism and major bleeding events were recorded from the time of VKA suspension to 30 ± 2 days postprocedure or until the next chemotherapy. Overall, 156 patients (56.4% at low risk and 43.5% at high risk for thrombosis) were enrolled; 34.6% underwent major surgery, 40.4% nonmajor surgery, and 25% chemotherapy. Thrombotic events occurred in five patients [3.2%, 95% confidence interval (CI): 1.41-7.27], four belonging to the high-risk and one to the low-risk group. Major bleeding occurred in five patients (3.2%, 95 CI: 1.41-7.27), all belonging to the high-risk group (three during major surgery and two during chemotherapy). In conclusion, LMWH given at fixed subtherapeutic is a feasible and relatively safe approach for bridging therapy in cancer patients on long-term VKA.

Safety of plasma-derived protein C for treating disseminated intravascular coagulation in adult patients with active cancer.

Cancer-related disseminated intravascular coagulation (DIC) is a life-threatening condition for which no effective treatment is currently available. Protein C (PC), a modulator of coagulation as well as the inflammatory system, has been successfully tested (in its activated recombinant form [a-rPC]) in sepsis-related coagulopathy, but with an increased risk for major bleeding. Plasma-derived PC (pd-PC) is more suitable than a-rPC in patients at high risk from bleeding due to its self-limiting process. We carried out a single-arm study evaluating the role of pd-PC in adult cancer patients with overt DIC. Over a period of 3 years, we treated 19 patients with overt DIC and a PC plasma concentration <50%; all received PC concentrate (Ceprotin(®), Baxter) for 72 hr in adjusted doses to restore normal PC values (70-120%). Blood coagulation, haematological tests, and the DIC score were recorded after 12, 24, 48 hr, 7 and 10 days, while clinical outcomes (bleeding, thrombosis and mortality) were recorded up to 28 days. Within 48 hr of starting pd-PC therapy, laboratory tests as well as the DIC score improved in all patients. At 28-days follow-up, no bleeding or thrombosis was observed. This is the first study to investigate the use of pd- PC for treatment of cancer-related overt DIC.

Residual vein thrombosis for assessing duration of anticoagulation after unprovoked deep vein thrombosis of the lower limbs: the extended DACUS study.

The safest duration of anticoagulation after idiopathic deep vein thrombosis (DVT) is unknown. We conducted a prospective study to assess the optimal duration of vitamin K antagonist (VKA) therapy considering the risk of recurrence of thrombosis according to residual vein thrombosis (RVT). Patients with a first unprovoked DVT were evaluated for the presence of RVT after 3 months of VKA administration; those without RVT suspended VKA, while those with RVT continued oral anticoagulation for up to 2 years. Recurrent thrombosis and/or bleeding events were recorded during treatment (RVT group) and 1 year after VKA withdrawal (both groups). Among 409 patients evaluated for unprovoked DVT, 33.2% (136 of 409 patients) did not have RVT and VKA was stopped. The remaining 273 (66.8%) patients with RVT received anticoagulants for an additional 21 months; during this period of treatment, recurrent venous thromboembolism and major bleeding occurred in 4.7% and 1.1% of patients, respectively. After VKA suspension, the rates of recurrent thrombotic events were 1.4% and 10.4% in the no-RVT and RVT groups, respectively (relative risk = 7.4; 95% confidence interval = 4.9-9.9). These results indicate that in patients without RVT, a short period of treatment with a VKA is sufficient; in those with persistent RVT, treatment extended to 2 years substantially reduces, but does not eliminate, the risk of recurrent thrombosis.

Residual vein thrombosis and D-dimer for optimizing duration of anticoagulation in idiopathic deep vein thrombosis.

Long-term anticoagulant treatment is highly effective in preventing recurrent Venous Thrombo-Embolism (VTE) in patients with idiopathic Deep Vein Thrombosis (DVT) of the lower limbs, though associated with an increased risk for major bleeding that may offset the benefits of anticoagulation. Accordingly to recent guidelines, patients with idiopathic DVT should be treated for at least 3 months and then should be evaluated for the risk-benefit ratio of long-term therapy. However, such 'time for decision' is often unclear and the optimal duration of VKA remains debatable. In recent studies, markers for the assessment of the individual risk for recurrent thrombosis have been proposed, which can be of help to establish the optimal duration of VKA treatment; among them, the D-dimer (D-d) assay and the Residual Vein Thrombosis (RVT) assessment by Compression Ultra-Sonography (CUS) were shown to be the most suitable. Studies' results showed that negative results of these parameters after 3 to 6 months of therapy, identify a group of patients at low-risk for recurrent thrombosis in whom VKA treatment can be withheld. In the present review we will discuss advantages and potential limits of using these individual markers for the management of patients with a first episode of DVT of the lower limbs.

Drug-related cardiotoxicity for the treatment of haematological malignancies in elderly.

Several publications have focused on the cardiotoxicity of specific classes of hematological therapeutic agents such as antracyclines and cyclofosfamide. Cardiotoxicity of cancer chemotherapeutics is a problem for patients of all ages, but it increases with age. Toxicity can also develop months after the last chemotherapy dose, and late reactions can be seen years later when they present as new-onset cardiomyopathy. No data are available about the cardiotoxicity of non-chemotherapy agents currently used as preferred therapy for hematological malignancy in elderly. In this review we have provided a summary of the cardiovascular toxic effects produced by different drugs and therapeutic agents. Early identification of patients who are at risk for cardiotoxicity should be a primary goal for hematologists in the development of personalized antineoplastic therapeutic strategies or interventions. Thus, the discovery of new biomarkers to identify patients at a high risk for the development of these complications is a high priority. Although targeted therapies such as imatinib and anti-CD20 antibody such rituximab are considered less toxic and better tolerated by patients compared with classic chemotherapy drugs, certain cardiological complications can be very serious and as these agents have been in use for a limited period of time.

Relapsing or refractory idiopathic thrombotic thrombocytopenic purpura-hemolytic uremic syndrome: the role of rituximab.

Idiopathic thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) is a rare disease responsive to treatment with plasma exchange (PE) but with a high percentage of relapse or refractory patients. A severe deficiency of ADAMTS-13 (<5% of normal activity), congenital or caused by an autoantibody, may be specific for TTP and it has been proposed that severe ADAMTS-13 deficiency now defines TTP. B cells play a key role in both the development and the perpetuation of autoimmunity, suggesting that B-cell depletion could be a valuable treatment approach for patients with idiopathic TTP-HUS. This review of the literature focuses on the role of rituximab, a chimeric monoclonal antibody directed against CD20 antigen expressed by B lymphocytes, in patients with relapsing or refractory TTP-HUS with or without ADAMTS-13 deficiency, suggesting that rituximab may produce clinical remission in a significant proportion of patients. Rituximab therapy reduces plasma requirement and avoids complications related to salvage-immunosuppressive therapy. In conclusion, rituximab provides an effective, well-tolerated, and safe treatment option for patients with idiopathic TTP-HUS, thus giving an alternative approach to the current treatment based on PE.